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Posts Tagged ‘dark matter’

Scientists Detect ‘Dark Lightning’ Energy Burst Linked to Visible Lightning

April 25, 2013 1 comment

Apr. 24, 2013 — Researchers have identified a burst of high-energy radiation known as ‘dark lightning” immediately preceding a flash of ordinary lightning. The new finding provides observational evidence that the two phenomena are connected, although the exact nature of the relationship between ordinary bright lightning and the dark variety is still unclear, the scientists said.

Three images, left to right, of the same thundercloud depict a less-than-10-milliseconds-long sequence of events: (left) formation within the cloud of a small channel, or ‘leader,’ of electrical conductivity (yellow line) with weak emission of radio signals (ripples), to (middle) a burst of both dark lightning (pink) and radio waves (larger ripples), to (right) a discharge of bright lightning and more radio waves. (Credit: Studio Gohde)

“Our results indicate that both these phenomena, dark and bright lightning, are intrinsic processes in the discharge of lightning,” said Nikolai Østgaard, who is a space scientist at the University of Bergen in Norway and led the research team.

He and his collaborators describe their findings in an article recently accepted in Geophysical Research Letters — a journal of the American Geophysical Union.

Dark lightning is a burst of gamma rays produced during thunderstorms by extremely fast moving electrons colliding with air molecules. Researchers refer to such a burst as a terrestrial gamma ray flash.

Read more:http://www.sciencedaily.com/releases/2013/04/130424210319.htm

WISE survey uncovers millions of black holes


 

WISE survey uncovers millions of black holes

 
 

 

 

 

 

 

 

 

 

With its all-sky infrared survey, NASA’s Wide-field Infrared Survey Explorer, or WISE, has identified millions of quasar candidates. Image credit: NASA/JPL-Caltech/UCLA

(Phys.org)—NASA’s Wide-field Infrared Survey Explorer (WISE) mission has led to a bonanza of newfound supermassive black holes and extreme galaxies called hot DOGs, or dust-obscured galaxies.

Images from the telescope have revealed millions of dusty black hole candidates across the universe and about 1,000 even dustier objects thought to be among the brightest ever found. These powerful galaxies, which burn brightly with infrared light, are nicknamed .

“WISE has exposed a menagerie of hidden objects,” said Hashima Hasan, WISE program scientist at NASA Headquarters in Washington. “We’ve found an asteroid dancing ahead of Earth in its orbit, the coldest star-like orbs known and now, supermassive black holes and galaxies hiding behind cloaks of dust.”

WISE scanned the whole sky twice in infrared light, completing its survey in early 2011. Like night-vision goggles probing the dark, the telescope captured millions of images of the sky. All the data from the mission have been released publicly, allowing astronomers to dig in and make .

Read more: http://phys.org/news/2012-08-wise-survey-uncovers-millions-black.html

 

CERN’s Large Hadron Collider Experiments Bring New Insight Into Matter of the Primordial Universe


ScienceDaily (Aug. 13, 2012) — Experiments using heavy ions at CERN’s Large Hadron Collider (LHC) are advancing understanding of the primordial Universe. The ALICE, ATLAS and CMS collaborations have made new measurements of the kind of matter that probably existed in the first instants of the Universe. They will present their latest results at the 2012 Quark Matter conference, which starts August 13 in Washington DC. The new findings are based mainly on the four-week LHC run with lead ions in 2011, during which the experiments collected 20 times more data than in 2010.

Heavy-ion collision recorded by ALICE in 2011. (Credit: CERN)

Just after the Big Bang, quarks and gluons — basic building blocks of matter — were not confined inside composite particles such as protons and neutrons, as they are today. Instead, they moved freely in a state of matter known as ‘quark-gluon plasma’. Collisions of lead ions in the LHC, the world’s most powerful particle accelerator, recreate for a fleeting moment conditions similar to those of the early Universe. By examining a billion or so of these collisions, the experiments have been able to make more precise measurements of the properties of matter under these extreme conditions.

“The field of heavy-ion physics is crucial for probing the properties of matter in the primordial Universe, one of the key questions of fundamental physics that the LHC and its experiments are designed to address. It illustrates how in addition to the investigation of the recently discovered Higgs-like boson, physicists at the LHC are studying many other important phenomena in both proton-proton and lead-lead collisions,” said CERN Director General Rolf Heuer.

Read more: http://www.sciencedaily.com/releases/2012/08/120813115445.htm

 

 

Astronomers in Chile spot evidence of dark galaxies


AAP  July 12, 2012

CHILE-SPACE

A photo released on July 9, 2012, of the Cats Paw Nebula revisited in a combination of exposures from the MPG/ESO 2.2-metre telescope in Chile with 60 hours of exposures on a 0.4-metre telescope taken by amateur astronomers Robert Gendler and Ryan M. Hannaho. Source: AFP

ASTRONOMERS in Chile using a powerful telescope have observed what appears to be evidence of the existence of dark galaxies, the European Southern Observatory (ESO) says.

Dark galaxies are small, gas-rich galaxies from the early universe that are believed to be the building blocks of today’s bright, star-filled galaxies, said the ESO, an intergovernmental organisation supported by 15 countries.

“For the first time, dark galaxies – an early phase of galaxy formation, predicted by theory but unobserved until now – may have been spotted,” the observatory said in a statement on Wednesday.

“Using ESO’s Very Large Telescope, an international team thinks they have detected these elusive objects by observing them glowing as they are illuminated by a quasar,” the statement said.

Read more: http://www.news.com.au/technology/astronomers-spot-evidence-of-dark-galaxies/story-e6frfro0-1226424613498#ixzz20ONE74R1

Belching Black Hole Proves a Biggie: First Known ‘Middleweight’ Black Hole


July 10, 2012

  • ScienceDaily (July 9, 2012) — Observations with CSIRO’s Australia Telescope Compact Array have confirmed that astronomers have found the first known “middleweight” black hole.

Galaxy ESO 243-49, about 300 million light-years away, is home to the newly found black hole. An arrow shows the location of the black hole HLX-1 in the galaxy ESO 243-49. (Credit: NASA, ESA and S. Farrell (U. Sydney))
 

Outbursts of super-hot gas observed with a CSIRO radio telescope have clinched the identity of the first known “middleweight” black hole, Science Express reports.

Called HLX-1 (“hyper-luminous X-ray source 1”), the black hole lies in a galaxy called ESO 243-49, about 300 million light-years away.

Before it was found, astronomers had good evidence for only supermassive black holes — ones a million to a billion times the mass of the Sun — and “stellar mass” ones, three to thirty times the mass of the Sun.

“This is the first object that we’re really sure is an intermediate-mass black hole,” said Dr Sean Farrell, an ARC Postdoctoral Fellow at the University of Sydney and a member of the research team, which included astronomers from France, Australia, the UK and the USA.

Read more: http://www.sciencedaily.com/releases/2012/07/120709102720.htm

In a Cosmology Breakthrough, Astronomers Measure a Filament of Dark Matter


By Rebecca Boyle 07.05.2012

Invisible, cold dark matter plays a major role in the evolution of galaxies, according to modern cosmological theory. The most advanced simulations of cosmic evolution show stringy tendrils of mass — dark matter — connecting giant clusters of galaxies via a vast cosmic web. Now for the first time, astronomers have been able to detect one of these filaments, sussing out its location by watching it warp light.

Neutrons Escaping to a Parallel World?


ScienceDaily (June 15, 2012) — In a paper recently published in European Physical Journal (EPJ) C, researchers hypothesised the existence of mirror particles to explain the anomalous loss of neutrons observed experimentally. The existence of such mirror matter had been suggested in various scientific contexts some time ago, including the search for suitable dark matter candidates.

 

Researchers hypothesize the existence of mirror particles to explain the anomalous loss of neutrons observed experimentally. (Credit: © Pix by Marti / Fotolia)
 

Theoretical physicists Zurab Berezhiani and Fabrizio Nesti from the University of l’Aquila, Italy, reanalysed the experimental data obtained by the research group of Anatoly Serebrov at the Institut Laue-Langevin, France. It showed that the loss rate of very slow free neutrons appeared to depend on the direction and strength of the magnetic field applied. This anomaly could not be explained by known physics.

Berezhiani believes it could be interpreted in the light of a hypothetical parallel world consisting of mirror particles. Each neutron would have the ability to transition into its invisible mirror twin, and back, oscillating from one world to the other. The probability of such a transition happening was predicted to be sensitive to the presence of magnetic fields, and could therefore be detected experimentally.

Read more : http://www.sciencedaily.com/releases/2012/06/120615104347.htm